Lamp base and socket



Jan. 11, 1944.

F. D. BRYANT LAMP BASE AND SOCKET Filed Jan. 14, 1943 lnvewkor" Frank D. BTHGTTlT,

His Art torneg.

Patented Jan. 11, 1944 LAltfl BASE AND SOCKET Frank D. Bryant, Wethersfield, 'Conn., assignor to General Electric Company, a corporation of New York Application January 14, 1943, Serial No. 472,330

Claims.

My invention relates to bases and sockets for electric lamps and similar devices, more especially electric lamps having elongated envelopes with bases at both ends which engage suitably spaced sockets.

An object of my invention is to provide sockets and bases which will aiford safety from contact or grounding of the live parts, and which will also afford convenient and reliable insertion and removal of the lamp from its sockets. Further objects and advantages of my invention will appear from the following detailed description of a species thereof and from the drawing.

. Figure 1 is an elevation, in section, of an assembled base and socket for one end of the lamp in accordance with my invention; Figure 2 is an elevation in section taken along the line 2-2 in Figure 1; Figure 3 is a perspective view of the base and the contact clip of the socket; and Figure i is a perspective view of the socket.

Referring to the drawing, the lamp comprises an elongated tubular glass or quartz envelope It which may contain an electrode in each end where the device is a discharge lamp or, in the case of an incandescent lamp, a filament extending longitudinally from end to end of the envelope. The base comprises a body portion H of insulating material, preferably porcelain. The said body portion is secured to the end of the envelope by means of a metal skirt l2 which is secured to an enlarged shoulder 13 on the said body portion. Before the shell I2 is slipped over the end of the tube H], a thin strip l4 of asbestos paper moistened with a solution of sodium silicate is wrapped about the tube. The shell I2 is secured firmly in place by a suitable clamping strip I5. The outer end of the body portion ll carries a spade-shaped metal contact prong [3 which extends outwardly therefrom and longitudinally of the lamp envelope Hi. The said prong i5 is connected by a flexible conductor I! to the end of a lead-in wire which extends through a seal 18 and is electrically connected to the electrode or filament in the envelope [0.

The socket comprises a, housing l8 within which is mounted a metal contact clip 20. The said contact clip 29 comprises a pair of fingers 2l-2l which are spaced apart at their lower ends and are provided with opposed V-shaped portions 22-22 whereby the contact prong I6 is insertable therein by moving it upward from the position shown in Figure 3 and then rotating it through an angle of 90 so that the flattened outer end portion of the contact I6 is gripped between the V-shaped portions 22-22 of the contact fingers. The upper ends of the fingers ill-2| are bent outward and riveted to a metal plate 23 which is secured to the upper end of the housing by an internally threaded eyelet or rivet 24 to which is attached a current supply conductor 25.

Elasticity is provided to the fingers 2i-2l by spring fingers 2l-2I which tend to compress the ends of the said fingers 2l-2l. The front face of the housing 19 is provided with a narrow vertical slot 26 which extends upward from the lower edge of the housing in alignment with the space between the lower ends of the contact fin gers 2 5-21, The said slot 26 is sufficiently wide to receive the stud portion 21 of the contact prong The said front face of the housing I9 is also provided with a recess 28 which extends around the margin of the slot 26. The said recessed portion 28 is slightly wider than a reduced circular shoulder portion 29 on the outer end of the body portion ll of the base. The lower end of the housing 19 is chamfered at 3G to make easier the insertion of the contact prong I6 into the slot 26.

The socket is mounted on a suitable supporting surface by inserting the rectangular upper end portion 3! into a correspondingly shaped opening in the support surface and inserting screws or bolts into the surface through slots 32-32 in laterally-extending aprons 33-33 on the housing.

The socket is provided with a wire bail 34 which surrounds the lamp base II and serves to catch the lamp if for some reason it should drop out of its socket. When inserting the lamp into the socket, the bail 34 is swung counterclockwise (Fig. 1) beyond the lower end of the socket housing I9.

To mount the lamp in its sockets it is held in the position shown in Figure 3 and then moved upward so that the contact prongs l6 at the ends of the lamp enter the slots 26. This upward movement is continued until the flattened outer end portion of the prong l6 strikes the converg ing portions 35-35 of the fingers 2 l-2 l Thereupon, the lamp is rotated through an angle of so that the flattened end portion of the prong I6 is gripped by the V-shaped portions 22-22 of the fingers 2I-2l. During the movement of the prong l6 through the slot 26, the shoulder portion 29 of the base moves through the recess 28. The said recess 28 and shoulder 29 coact to prevent a piece of wire or other foreign object from dropping between the base and socket into contact with the live parts.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A double-ended electric lamp comprising an elongated envelope having a base at each end thereof, each of said bases having a spade-shaped metal contact and mounting prong extending outwardly therefrom and longitudinally of the lamp envelope, said prong comrising. a flattened outer end portion spaced from the end of the base an appreciable distance by a stud portion of reduced diameter.

2. A double-ended electric lamp comprising an elongated envelope having a base at each end thereof, each of said bases comprising a body portion of insulating material extending. outward 1y from the lamp envelope and terminating at its outer end in a reduced circular shoulder portion, and a spade-shaped metal contact and mounting prong extending outwardly from the shouldered end portion of said base and longitudinally of the lamp envelope, said prong comprising a flattened outer end portion spaced from the end of the base an appreciable distance by a stud portion of reduced diameter.

3. In combination, a lamp socket comprising a housing of insulating material having a slot in one face thereof'extending at its outer end to an edge of the said housing, the said one face being recessed along the edges of said slot, and a contact spring clip within said housing in alignment with said slot, and a lamp having a base comprising a body portion of. insulating material terminating at its end in a reduced circular shoulder portion with a spade-shaped metal contact and mounting prong extending outwardly from the shoulder end portion of the base, said socket and base being constructed and arranged for insertionof the base prong laterally into the slot in the socket from its outer end with subsequent rotation of the lamp and base to lock the flattened end of the spade-shaped prong in the socket clip, the said shoulder portion of the base being of such size as to fit in the recess along the slot.

4. A double-ended electric lamp comprising an elongated envelope having a base at each end thereof, each of said bases having a spade-shaped metal contact and mounting prong extending outwardly therefrom and longitudinally of the lamp envelope, said prong comprising a flattened outer end portion spaced from the end of the base an appreciable distance by a stud portion of reduced diameter, the diameter of said stud portion being substantially equal to the thickness of the said flattened outer end portion.

5. In combination, a lamp comprising an envelope having a base at an end thereof with a metal contact prong extending outward from the base axially of the envelope, said prong compris ing. a flattened outer end portion spaced from the. end of the base an appreciable distance by a stud portion of reduced diameter, and a socket comprising a hollow housing of insulating material having a slot in one face thereof extending at its outer end to an edge of said housing, and contact spring fingers within said housing in alignment with said slot, the said slot being slightly wider than the said stud portion and the thickness of the flattened portion of said prong. whereby said prong is insertablein said socket by pushing it, flattened portion edgewise, into the said slot from the outer end of the slot and sub- I sequently rotating the lamp and base to lock the saidflattened portion of the prong between the:

said spring fingers.

FRANK D. BRYANT. 

